1. Field of the Invention
This invention is related to the field of multiplexor circuits.
2. Description of the Related Art
Multiplexors are a basic building block of digital circuits. Generally, a multiplexor (mux) is a circuit used to select one of two or more inputs as an output responsive to selection control signals provided to the mux. Because they are frequently used, it is desirable for muxes to be high speed (have a low delay).
Unfortunately, wide muxes (e.g. greater than five inputs) are difficult to design with low delay. If a single level mux is designed, internal electrical loading (or the buffering used to alleviate the loading) generally increases the delay of the mux to approximately the same delay as two levels of smaller muxes (e.g. an 8 to 1 one mux can be accomplished with two 4 to 1 muxes, each receiving separate sets of 4 inputs, followed by a 2 to 1 mux coupled to receive the outputs of the 4 to 1 muxes). Thus, wide muxes are generally not designed, opting instead for the two level approach.